Keep them physically separate through a closed door, and watch them closely. Let the new cat explore, but be prepared! Watch their reactions to each other. Pearl (totally black with green eyes) other and make their introductions. 1. HOW TO INTRODUCE A SENIOR CAT TO YOUR CURRENT CAT 8. INTRODUCING YOUR CAT TO A NEW DOG: A STEP-BY-STEP GUIDE other’s scents and should be ready to meet each other. //